Like Chris (previous reviewer) said, you have to look beyond the common to find the gems on TripAdvisor - this is a great example.
You can park below the Napili General Store (limited spots), or up on Lower Hono.... (sp), and walk down to Napili Beach. (BTW, this is a 5 star beach! but few or no Honu) Once on the beach, go left (south), follow the 'trail'. Try and respect the Napili Pt private property as best you can - they paid for privacy!
It's a clamber down to the water - watch your step, its at your own risk. If the surf is high, this might not be your day, because... To get into the water, you have a step/slide/half jump into the water, and the rocks are shallow here. The best plan is to NOT DAWDLE - get your [--] together and get to open water ASAP. Be careful, and have a great time!
Ahhh - the water can be cold, don't overstay your welcome, maybe wear a rash guard. Sun can be fierce here, of course.